Vasoconstriction ergot alkaloids causing

Several chemical compounds may cause inflammation or constriction of the blood vessel wall (vasoconstriction). Ergot alkaloids at high doses cause constriction and thickening of the vessel wall. Allylamine may also induce constriction of coronary arteries, thickening of their smooth muscle walls, and a disease state that corresponds to coronary heart disease. The culprit is a toxic reactive metabolite of allylamine, acrolein, that binds covalently to nucleophilic groups of proteins and nucleic acids in the cardiac myocytes. 

Uses Postpartum bleeding (uterine subinvolution) Action Ergotamine derivative Dose 0.2 mg IM after placental deliv y, may repeat 2-4-h intervals or 0.2-0.4 mg PO q6-12h for 2-7 d Caution [C, ] Contra HTN, PRO Disp Inj, tabs SE HTN, N/V Interactions t Vasoconstriction W/ ergot alkaloids, sympathomimetics, tobacco EMS Tobacco use can t vasoconstriction and lead to a hypertensive crisis OD May cause N/V/D, chest/abd pain, limb numbness, and possibly distal gangrene d/t vasoconstriction activated charcoal may be effective for PO form... 

The hypertensive crisis that can follow the withdrawal of clonidine can be accentuated by beta-blockers. It has also been reported that when beta-blockers are used in conjunction with drugs that cause arterial vasoconstriction they can have an additional effect on peripheral perfusion, which can be hazardous. Thus, combining beta-blockers with ergot alkaloids, as has been recommended for migraine, can cause severe peripheral ischemia and even tissue necrosis (408). 

Ergot alkaloids are contraindicated in women who are or may become pregnant, because the drugs may cause fetal distress and miscarriage. Ergot alkaloids also are contraindicated in patients with peripheral vascular disease, coronary artery disease, hypertension, impaired hepatic or renal fnnction, and sepsis. Ergot alkaloids should not be taken within 24 honrs of the use of the triptans, and should not be nsed concnrrently with other drugs that can cause vasoconstriction. 

Vessels Ergot alkaloids can produce marked and prolonged a receptor-mediated vasoconstriction. An overdose can cause ischemia and gangrene of the limbs. 

F. Propranolol may worsen vasoconstriction caused by ergot alkaloids. 

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